Project Description: The primary function of the GOES NOP Spacecraft Support Ground System (SSGS) is to ingest raw data from the GOES NOP Imager and Sounder instruments; retransmit radiometrically corrected, gridded (Imager data only), and earth located data to the GOES spacecraft in the Level 1b GOES Variable (GVAR) format for broadcast to the Satellite Operations Control Center (SOCC) in Suitland, Maryland and to primary users, process the GVAR data stream (primarily at the NSOF to obtain data needed for orbit and attitude determination, and monitor the quality of the broadcast data. The prinGOESal elements of the SSGS involved in the performance of these functions are: the Sensor Processing System (SPS), the Rehosted Product Monitor (RPM), and the Orbit and Attitude Tracking System (OATS).

The SPS is responsible for instrument data pre-processing, reformatting of data into the GVAR format, and providing support functions for OATS. The data pre-processing functions include frame synchronization, decommutation by channel, detector scan alignment, visible image normalization and infrared radiometric calibration, among others. The SPS also forwards the modulated GVAR signal to the GOES Command and Data Acquisition (CDA) transmitter for uplink to the spacecraft. Support functions provided by the SPS for OATS include spacecraft ranging, instrument star sense data processing, periodic Image Motion Compensation (IMC) and servo error data extraction for transmission to OATS.

The RPM is responsible for GVAR data quality monitoring, extracting orbit and attitude data from the GVAR data stream, and providing landmark measurement data to OATS in the form of earth location coordinates for further processing.

The OATS is responsible for several functions using inputs received from the SPS and RPM (as described above). These functions include orbit and attitude-related computations and processing, generation of command data for spacecraft maneuvers, and supporting the GOES NOP Telemetry and Command System (GTACS) in generating spacecraft command schedules.

The GOES NOP ground system has replaced the GOES I-M ground system operations, GOES-13 is operational as GOES East and GOES-14 becomes operational in December of 2011. A simplified schematic of the SSGS data flows for one GOES satellite is shown in the diagram below.